Actor Charlie Sheen has dramatically increased awareness of people living with HIV after opening up about his diagnosis.

The former Two and a Half Men star opened up about his HIV status last year, in a bid to end a “cycle” of blackmail, extortion and tabloid rumours.

The actor claimed he had paid out millions to “blackmailers” to ensure the news remained secret, but claims he did not put anyone at risk.

Research has this week found that Sheen’s admission has massively boosted public awareness of HIV/AIDS, and that the announcement was many times more effective than most publicity initiatives.

Professor John Ayers, from San Diego State University noted the effect in the Journal of the American Medical Association, – revealing that HIV-related Google seaches surged by more than 400 percent on the day Sheen revealed his HIV status, with 2.75 million extra searches

Searches as “HIV testing” and “find HIV testing” increased by over 214%, while searches for HIV symptoms increased by 540%.

Sexual health related searches, such as looking to get condoms, were also massively up. Meanwhile, there were more than 6,500 news stories centred on HIV – unprecadented since the height of the AIDS crisis.

Professor Ayers wrote: “While no one should be forced to reveal their HIV status and all diagnoses are tragic, Sheen’s disclosure may benefit public health by potentially helping many learn more about HIV and HIV prevention.

“More must be done to make this benefit larger and lasting.”

Co-author Eric Leas of the University of California San Diego noted: “Celebrity disclosures are not new to HIV, with Rock Hudson and Magic Johnson serving as noteworthy examples.

“Yet, Sheen’s disclosure could be different. The Web 2.0 era may heighten the impact of Sheen.

“With Sheen, unlike with Magic Johnson for instance, we have smartphones in our pockets that we can easily use to learn about HIV within seconds with a single search or click.

“At the same time, social media can expand the effect of Sheen’s disclosure beyond the initial television broadcast as networks form around celebrities.”

Professor Ayers added: “Sadly, the public health community may be missing the mark.

“I’m unaware of any major HIV educational campaigns that are using Sheen’s disclosure for public health outreach.”

“Sheen is a controversial figure and it’s incredibly hard to frame public health messages around a figure whose behaviour, not unlike any non-celebrity or myself, may at times conflict with public health science.”

Sheen has since caused controversy by pursuing ‘alternative’ treatments with no scientific basis.